Process for preparing improved carpet yarn



United States Patent O U.S. Cl. 264-210 Claims ABSTRACT OF THEDISCLOSURE The invention provides a process for preparing a carpet yarnfrom a dispersion of polyester in fiber-forming synthetic linearpolyamide, especially poly-l-caproamide by selectively controling thespinning, drawing, crimping and aftertreating conditions whereby a yarnhaving excellent pattern definition, superior resilience and a velvetysheen is produced.

BACKGROUND OF THE INVENTION This application is a divisional of US.application Ser. No. 679,202 filed on Oct. 30, 1967, and now abandoned.

This invention relates to a process for producing multifilament yarnfrom a dispersion of fiber-forming polyester in fiber-forming polyamidegenerally in accordance with US. Pat. 3,369,057, dated Feb. 13, 1968, toTwilley. Carpet yarn is required to meet high standards of uniformity inperformance in carpet-making operations including dyeing in a hotaqueous bath and tufting by passing loops through a backing sheet. Inaddition to uniform performance, the yarn must have high performance interms of retaining its appearance under conditions of wear and soiling;and in addition is required to develop high bulk in the final carpet sothat a given weight of yarn will sufiice for making a relatively largearea of carpet. For example, where wool is used at a weight of say 30-40ounces per square yard, a synthetic fiber with good bulk can be used atweights in the range of -20 ounces per square yard.

Besides the fundamental properties above mentioned of uniformperformance, durability and high bulk or cover, carpt yarns are valuedfor their ability to produce pleasing aesthetic effects. Among theeffects desired are a springy yielding to the touch, so that the carpetpile yields without flattening completely under gentle pressure, thenreturns promptly to its original height; good pattern definition, i.e.,clear delineation between areas of different pile height in a tuftedcarpet; sparkle giving an effect of depth; velvetlike sheen in cut orsheared pile constructions.

SUMMARY OF THE INVENTION In accordance with the present invention aprocess for producing multifilament textured yarn is provided whichcomprises extruding through a multihole spinnerette a moltenfiber-forming polyamide having a polyester dispersed therein in weightproportions of about 90:10 to 60:40 of polyamide:polyester to form amultiplicity of filaments. Each of the filaments are formed from an eX-trudate hole providing a capillary area of 7X10- to 12 10- square inchesand attenuated while in a molten condition within the quench stack by adraw-down ratio of about 70 to 120. The capillary area may be composedof a single hole of any desired configuration or a plurality of closelyspaced holes. After solidification, the filaments are stretched about3.5 to 5 times their original length whereby the resulting filamentshave a denier of 3,549,741 Patented Dec. 22, 1970 about 5 to 20. Inorder to improve the bulk or covering power of the yarn, an average ofat least about 8 crimps per inch is imparted to the yarn in apparatussuch as stutter-box crimpers, steam jet texturing devices and gear-typecrimpers. The high cover and better pattern definition characteristicsare further enhanced by correlating the crimping and an after crimpstretching operation to confer crimp elongation off the package notabove about 10 percent while maintaining crimp elongation after boil inthe range of 15 to 40 percent. The after crimp stretching operationinvolves stretching the filaments an additional 5 to 15 percent beyondtheir true length.

PREFERRED EMBODIMENTS OF THE INVENTION The process of this inventionemploys a dispersion of polyester in polyamide, in particular from adispersion of about 10-40 parts by weight polyethylene terephthalate incorrespondingly -60 parts poly-l-caproamide. This polycaproamide, asdisclosed in the above-cited US. Pat. No. 3,369,057 to Twilley, musthave a low level of primary amino groups. A prefered level is in a rangefrom about 5 to about 20 meq. per kg. (i.e., milliequivalents of primaryamino groups per kilogram of polycaproamide). The polyester must be welldispersed, as accomplished for example by mixing and melting thepolyamide and polyester together in a melt extruder wherein the mixtureis sheared by rotation of the screw, then forwarding the melt throughpipes at a velocity to maintain shearing conditions and passing the meltthrough a filter of finely divided material such as sand or sinteredmetal particles.

The operations thus far outlined are in accord with one conventionalpractice for spinning nylon. However, to obtain filaments ofsatisfactory quality with respect to denier uniformity and freedom frombreaks while opcrating at high production rates in the spinning anddrawing process, it has now been found that an unusually large area forthe capillary or capillaries making up each of the spinnerette holesshould be used, viz, an area totaling about 7X 10- to 12 10 square inchper spinnerette hole, as obtained, e.g., with three capillaries groupedclosely together in one hole so as to form three streams of melt whichcoalesce to a trilobal filament, each capillary having diameter of about18-22 mils. The capillaries commonly used similarly for spinning oftrilobal nylon yarn are 14 mils in diameter; thus the capillaries usedin melt spinning in accordance with the invention have areas from about65 to percent greater than that of the holes normally used for spinningnylon of the same viscosity as the polycaproamide nylon used in thesubject dispersions. Multilobal or other modified off round filamentcross sections are preferred, both for their greater cover and forbetter sparkle than round cross sections. Particularly suitable crosssections are the trilobal cross sections disclosed and claimed in US.Pat. No. 3,216,186 dated Nov. 9, 1965 to Opfell.

The diameter of the uncrimped, drawn filaments of the present inventionis generally in the range giving a denier per filament of about 5-20.This diameter is attained, from the filament as extruded through theholes, by a combination of attenuating or drawing down the moltenfilament and permanently streaching or drawing the solidified filament.The attenuation or stack draw down can be calculated from the volumetricthroughput q, the capillary area A, and the windup speed S by theformula: Attenuation=SA/q (the quantities being expressed in consistentunits). In the present invention the attenuation is maintainedconsiderably above normal levels, viz, about 70-120 versus about 40-50for nylon spinning.

Moreover, in the filaments of the present invention, it is found thatthe final draw ratio of the solidified filament must be in the rangebetween about 35:1 and :1 as measured by the ratio of peripheral speedof the final draw rollzspeed of feed roll supplying the undrawn yarn tothe draw zone. Thereby the solidified filament is molecularly orientedalong its length as shown for example by X-ray. For good uniformdyeability this orientation should be substantially uniform; and suchcan be achieved in the filaments of this invention by use of the aboverange of draw ratio, while at the same time good drawing performance canbe obtained, i.e., low bundle breaks and low breaks of individualfilaments causing the filament to wrap about the draw roll.

Preferably, the ultimate elongation (UE) and ultimate tensile strength(UTS) of the uncrimped yarn of this invention, both as measured on theInstron tensile tester, are in the ranges of 25 to 75 percent UE andabout 2.6 to 6 grams per denier UTS.

These drawn, oriented filaments are preferably about 8 to 20 denier andcontain polyester microfibers dispersed therein, mostly orientedlengthwise of the filament axis. The microfibers are too fine, in thedrawn filaments, to be observable in cross section under an opticalmicroscope, but can be observed using the electron microscope. Thesediameters generally average in the range from about 0.02 to 0.3 microndepending upon factors such as fineness of the dispersion of moltenpolyester in molten polyamide, draw ratio used, etc. Their lengthexceeds their diameter by manyfold, generally at least 250-fo1d.

To attain the property of cover or bulk, a drawn feeder yarn must betextured or crimped. The above-described drawn yarn is found to be wellsuited to taking a good crimp. An angular crimp is particularly suitableas obtained, for example, by steam jet crimping against a wad of crimpedyarn or by stuffer box crimping. Steam jet crimping against a wadproduces a random angular crimp in which the irregularities blend outoverall to give satisfactory uniformity. In stutfer box crimped yarn,the crimping can be and desirably is controlled for uniformity withinabout :20 percent in terms of crimps per inch. A suitable range foraverage crimps per inch is about 8 to-17. The UE of the yarn beingcrimped influences the crimp uniformity, since too high UE results instreaching the yarn instead of feeding it forward for crimping.

Crimp elongation off the package and crimp elongation after boil areimportant characteristics which must be kept uniform within at least therange of :5 percentage units. The average crimp elongation off thepackage should not exceed 10 percent, and the average crimp elongationafter boil should be in the neighborhood of to 40 percent for thetextured yarns of this invention. 1

The above crimp parameters can be defined with respect to the diagramwhich appears below.

ELBOW (a) Leg Length is the distance between midpoints of the bends inthe filament.

(b) Elbow is the midpoint of the filament bend.

(c) Crimp Angle is the angle formed by two legs on either side of anelbow.

(d) Crimp/Inch is equal to one-half the number of leg lengths in an inchof filament (an inch as measured when the filament is straightened out,i.e., when the crimp angle is fully open). Crimp/ Inch is measured bycounting the total number of elbows in an inch of straightened filamentand dividing by two.

(e) Crimp is the combination of Crimp/Inch (Leg Lengths) and crimpangles which makes textured yarn different from normal drawn yarn.

Crimp elongation is measured by hanging a length of the crimped yarnunder an added load of 0.1 gram per denier for a period of 2 seconds(length L under which condition the crimp angle is largely straightenedout (i.e., brought practically to 180), and then removing the load andagain measuring the length of the same fiber hanging under no addedweight after an elapsed time of at least 15 seconds (length L Thepercent crimp elongation (CE) is calculated as:

Crimp elongation off the package is the value obtained for the yarnwithdrawn from the package for use in carpet making, particularly intufting. It is of critical importance in the tufting process that thisvalue be not over 10 percent, since the control of the size of loopsdepends upon following, with the yarn, the motion of the tufting needle.If the yarn stretches excessively, the needle motion will not befollowed with sufficient accuracy. It will be appreciated that the hot,humid conditions often found during the summer months in carpet millsmay increase the crimp elongation otf the package by the same action asin dyeing (discussed below); thus it is important that the crimpelongation off the package be stable under such humidity conditions.This is one of the respects in which the present yarn shows unexpectedsuperiority over similar nylon yarns, for reasons not entirelyunderstood.

Crimp elongation after boil is the value of the crimp elongationmeasured as described above, after subjecting the yarn, as removed fromthe package, to boiling water for one hour under no tension. The samevalue can be obtained more quickly by subjecting the yarn to a steamspray. It represents a sharpening of the crimp angle from about 130 inthe yarn as it comes off the package to about 110 to representing achange of crimp elongation due to boiling, from a maximum of 10 percentoff the package to a range between about 15 percent and about 40 percentafter boil. This 1540 percent range after boil is critical to give theyarn of the present invention its high cover combined with itscapability of achieving exceptionally good pattern definition betweenhigh and low areas in the pile of a tufted carpet. With the presentyarns, a crimp elongation after boil materially less than 15 percentresults in insufiicient bloom or spreading out of the tufts under theinfluence of hot, Wet conditions as in dyeing, hence results inunsatisfactory cover. A crimp elongation after boil of greater thanabout 40 percent in these yarns, on the other hand, results in too tighta crimp so that the pile of a tufted carpet will pull down into a tightwad under the hot, wet conditions of dyeing, and will be tight againstthe backing rather than being high and bulky.

Crimp elongation after boil is determined primarily by the crimpingconditions in the zone where the crimp is first formed, ordinarily a hotzone. In mechanical crimping such as stuffer box crimping this heat willbe generated by the work done by the crimp rolls in bending the yarnagainst resistance of the yarn wad and the outlet gate; commonly it isnecessary to cool the rolls and/ or the crimping box to avoid fusion ofthe filaments. To reduce the work done on the filaments and thus reducethis heat generated in mechanical crimping, it is advantageous toplasticize the filaments by a pre-treatment under hot, moist conditions,e.g., with steam.

The primary factor determining crimp elongation off the package, andalso an important factor in determining crimp elongation after boil, ispost-treatment of the crimped yarn after it leaves the stulfer box.

The yarn of the present invention, it has been found, is moresusceptible to crimping than is nylon yarn of the same nylon used in thenylon/polyester dispersion from which the present yarn is produced.Moreover, the crimp imparted in the crimping box, in the hot zone of asteam jet, or otherwise in a hot zone is quite easily removed from thefreshly crimped yarn of the present invention,

it has been found. Accordingly, to produce the yarn of the presentinvention with not over 10 percent crimp elongation off the package andwith 1540 percent crimp elongation after boil, it is found that the yarnshould be crimped at about 8-17 average crimps per inch; and should thenbe cooled as it leaves the crimping zone. The cooled, freshly crimpedyarn must then be stretched by about -15 percent beyond its fullystraightened out length. This positive stretch should be adjusted toconfer crimp elongation off the package of not greater than percent, butshould be limited to maintain crimp elongation after boil of at leastpercent; the adjustment will usually give a positive stretch in theindicated range of 5-15 percent beyond the length of the yarn with thecrimps straightened out. This stretch can suitably be obtained in stageswhich first partially straighten out the crimp under light tension ofabout 0.1 g.p.d. to allow handling the yarn in nip rolls, then furtherstretching the yarn between rolls. Although the crimp elongation infreshly crimped yarn is quite easily reduced by stretching, neverthelessthis yarn after the usual dyeing operations at the boil will recovercrimp elongation and retain this recovered crimp with good permanency.Thus the processing required to obtain yarn for use in tufting isunexpectedly simple.

For use as feeder yarns for tufting, several ends of yarn as abovedescribed are plied together at say 2 to 10 turns per inch. The pliedyarns can be of varied type such as Saxony, Frieze or Cable styles.Saxony and Frieze yarns consist generally of 2 or 3 yarns plied at 48turns per inch twist in a twist direction opposite to the direction oftwist in the individual yarns. Cable type yarns can in general be madeby plying together more than 2 yarns with a ply twist of 1V: to 3 turnsper inch in the direction opposite to the twist in the individual yarns.The individual yarns employed in such plied structures can be spun yarnsmade from staple filaments, or continuous filament yarns which can haveup to 8 turns per inch of twist. The individual yarns can also containcohesive finishes or sizes, and can be cohered via interfilamentcommingling as described in U.S. patent application Ser. No. 535,480, ofF. W. Le Noir, filed Mar. 18, 1966.

When such plied yarns are heat-set, it is found that upon forming a pilecarpet and cutting or shearing off the loops, a high velvety sheen willbe produced in the resulting carpet. This capability of the presentyarns to produce such velvety sheen in a cut or sheared pile is astriking and valuable property.

The heat setting of plied yarns can be carried out continuously, orbatchwise. In any event, the yarn should preferably be in tensionlesscondition during heat setting to avoid removal of the crimp in thefilaments. In a continuous operation, tensionless treatment is bestachieved by subjecting the yarn to treatment while supported on a movingbelt. Superheated steam, as obtained in suitable autoclave apparatus, isgenerally the preferred form of heat treatment. Dye can be applied tothe plied yarn prior to heat setting to secure dye penetration and heatsetting in the same operation.

The yarns can be made to contain various additive ingredients whichimpart specialized properties. For example, ingredients which can beadded to the yarn either by incorporating within the polymer prior tospinning, or by after-treatments of the yarn or fabric include flameretardant agents such as compounds of antimony, phosphorus, andhalogens; titanium dioxide delustrant; antistatic agents; adhesionpromoting agents such as isocyanates and epoxides; heat and lightstabilizers such as inorganic reducing ions, metal ions such asmanganese, copper and tin, phosphites, and organic amines such asalkylated aromatic amines and ketone-aromatic amine condensates;thermally stable organic pigments such as 2,9-dimethylquinacridone andinorganic pigments such as titanium dioxide; fluorescent agents andbrighteners such as Tinopal PCR; cross-linking agents; bacteriostatssuch as phenols and quaternary amines; colloidal reinforcing particles;antisoiling coatings such as colloidal silica and boehmite; antistaticor antisoiling additives such as polyamino compounds or polyethers; andother known additives and treatments. It is essential however thatesentially no volatile ingredients such as water or solvents becontained by the polymer prior to extrusion since these are deleteriousto satisfactory extrudate coalescence. The presence of plasticizershowever is beneficial to extrudate coalescence, and these can be removedif desired after filament formation. In the case of polycaproamidepolymer, the presence of about 0.5-2 percent of monomeric lactam whichacts as a plasticizer, facilitates extrudate coalescence.

The above described continuous filaments of this invention can be cutinto staple and used in that form in pile carpets. Short staples orflock can likewise be produced and applied to a backing by conventionalflocking methods.

The yarn of this invention can be dyed to advantage with anthraquinonedyes, as disclosed and claimed in copending US. application Ser. No.548,381 of Ortheil et al. filed May 9, 1966; and also to advantage withdisperse azo dyes which are substituted by at least 2 electronattractingsubstituents, especially those of the group (CH X (n being an integerfrom 0 to 6 and X being halogen or -'C=-N), and NO Examples are thefollowing dyes identified by their code numbers of Colour Index, volume3, 2nd edition (1957)-The Society of Dyers and Colourists and TheAmerican Association of Textile Chemists and Colorists): Nos. 11100;11150; 11230; 11310; 11420.

As has already been noted, when the yarns of the present invention areemployed for tufting, they perform exceptionally well in the machine andallow a very exceptional sharp contrast between high and low pileregions, i.e., very superior pattern definition; and this is especiallytrue under humid and hot conditions such as 50 percent and higherrelative humidity at 20 C. or higher temperatures. The compressionalresilience of these yarns of this invention is also appreciably betterthan a like yarn from all nylon, as measured visually by recovery fromcompression under load or as measured by work recovery, i.e., area underthe stress-strain curve for recovery from 1 percent elongation: areaunder the stress-strain curve passing to 1 percent elongation of theuncrimped yarn. The stress-strain curves can be obtained for examplewith the Instron tensile tester. The improved compressional resilienceis found under hot, wet conditions as in dyeing as well as under normalconditions; and this compressional resilience during dyeing is one ofthe factors contributing to the superior pattern definition, since inpiece dyeing as commonly practiced for carpets the goods are packettogether so that the pile is compressed.

In the examples which follow, the polyamide used is poly-e-caproamide;however, the invention is not confined thereto and can be practicedsimilarly using other melt spinnable fiber-forming synthetic linearpolyamides of which polyhexamethylene adipamide (nylon 66),polyhexamethylene sebacamide (nylon 6, 10) and polyhendecanamide (nylon11), together with copolymers of these with other polyamide-formingunits, are representative examples.

EXAMPLES The following examples are illustrative of the presentinvention and of the best mode presently contemplated of carrying outthe invention; but the invention is not to be interpreted as limited toall details of the examples.

In the example of the table below, 70 parts by Weight of particles ofpoly-e-caproamide (having about 20 meq. of primary amino groups per kg.of polyamide) and 30 parts by weight of polyethylene terephthalate weremixed. The polycaproamide contained about 0.3% of titanium dioxidedulling agent and about ppm. of manganese as its chloride plushypophosphorous acid light stabilizer. The polycaproamide had relativeviscosity in aqueous 90% formic acid (by ASTM Test D-789-62T) of about56 and the polyethylene terephthalate had reduced viscosity of about0.83 dl./gm. as measured at C. and polymer concentration of about 0.5gram per 100 milliliters in purified orthochlorophenol containing 0.1%by weight of water. Moisture content was kept not above 0.04% in theincoming particle mixture.

This mixture was melted and fed by an extruder to a metering pump whcihsupplied a melt spinning pack comprising a finely porous filter and aspinnerette having 70 capillary holes, each of Y-shaped configuration.Each hole of Run A had area of 8.1 10 sq. ins. and the holes of Run Beach had area of 7.2 10 sq. ins. The extruder was operated to produce apressure of about 30003500 pounds per square inch at the outlet.

The temperature of the molten polymer at the pump was about 275 C. andthe temperature of the spinnerette pack was about 265 C. The moltenpolymer upon extrusion through the spinnerette descended a spinningtower in contact with air admitted at 82 F. and 65% relative humidity.After windup, the solidified yarn was drawn at 3.87:1 draw ratio. Thespinning, quinching, windup, and drawing operations were otherwiseessentially as described in U.S. Pat. 3,216,186, dated Nov. 9, 1965, toOpfell, at column 7, lines 1-30.

Although such was not done in the example of the table below, it isadvantageous, especially when using polyamide of high formic acidrelative viscosity such as 70100, to employ in the spinning tower aheated sleeve as described in Swanson et a1. U.S. application Ser. No.752,414 filed June 18, 1968, Example 1 thereof. The sleeve is heated toproduce, at a point one-half inch down from the spinnerette, atemperature in the range 320-380 C., and the sleeve extends suitably 3inches to 6 inches below the spinnerette to maintain a quiescentatmosphere in that zone. The sleeve temperature is adjusted to providegood spinning performance, and is held constant to :5 C. Too low atemperature results in nonuniform filament denier; and too hightemperature causes drips. Use thereof gives generally better spinningperformance and particularly, less variable spinning performance interms of drips due to filament breaks at the spinnerette. A preferredembodiment of this invention involves the use of such heating in thespinning tower and use of polycaproamide of high viscosity, viz. formicacid relative viscosity in the range 70100, and use of spinnerettes withthree closely spaced capillary holes as disclosed in U.S. Pat. 3,216,186of Nov. 9, 1965 to Opfell. These holes should have diameter of 0.018inch to 0.022 inch giving an area for each group of three holes of about7 10 to 12 10 sq. ins. Otherwise in such embodiment the operation is asdescribed for the above example.

Another variant over the Opfell procedure which can advantageously bepracticed with the present yarns is to use a larger draw pin or no drawpin and to omit the heater used by Opfell during drawing.

The resulting drawn yarn was supplied to a steam preheating chamberoperating at 100 C. and then to the feed rolls of a stuifer box crimper.In Run A the gate weight on the stuffer box was 1.5 pounds and in Run Bit was lb. The crimped yarn leaving the stuffer box was drawn (withoutcompletely straightening out the crimp) around a godet roll and then waspassed to a pair of nip rolls through which it was fed at about 1.35times the surface speed of the godet whereby the crimped yarn wasstraightened out and was stretched in the range of about 515% stretchbeyond its fully straightened out length. From these nip rolls the yarnpassed to a conventional winder operating with a tension of 175 gramsper 1200 denier, 70-filament end of yarn.

Further details of the spinning and drawing conditions and performance,and the properties of the yarn 8 produced before and after crimping, areshown in the table below.

Although multilobal yarn, especially trilobal yarn as above describedspun from a group of three closely adjacent holes is the preferredproduct of this invention, round yarn which has a crimp as abovedescribed is also within the ambit of this invention. Such round yarncan be spun from the above described melt through spinnerette holes ofdiameter about 14-22 mils, employing a spinning speed and stack drawdown correlated to obtain undrawn denier per filament of about 30-100;and then processed to textured yarn by the general procedure aboveoutlined.

TABLE Spinning and drawing conditions, performance, and physicalsExample:

Pounds spun and drawn 390 Spinning performance (drips per 1000 lbs.)

(variable from 0 to 13) 3 13 Undrawn yarn properties- Uster, percent 13Coefficient of filament denier variation 12 Denier (70-filament yarn)4430 Drawn yarn properties Denier 1200 UE, percent (Instron) 30:2 UTS,g.p.d. (Instron) 50:0.1 Tensile modulus (g.p.d.) 1 50:2 Drawingperformance- Wraps per pound 0.1 Breaks per pound 0.008 Spinningconditions- Exit polymer and block temp., C. 270 Extruder pressure,p.s.i.g 3000 Quench air, c.f.m., inlet/exhaust 70/63 Monomer exhaust,ins. water 4 Drawing conditions- Draw ratio 3.87 Heater temperature, C.185 Textured yarn physical properties Crimps per inch 10 Crimpelongation before boil, percent 9 Crimp elongation after boil, percent20:3 1 Slope of the first linear portion of the stress-strain curve(Instron) X 100.

Crimped yarn produced as above with the trilobal cross section of OpfellU.S. Pat. 3,216,186 has certain advantages in carpet over other trilobalyarns, in particular better resistance to fading upon exposure to ozone.

Crimped yarn of the Opfell cross section was employed in the productionof tufted carpet samples. In standard tests, these samples showedexcellent pattern definition, especially under humid conditions, andsuperior resilience together with satisfactory softness.

When this crimped yarn was twisted (4S-4Z) and the twist was heat set(steam at 15 p.s.i.g.) and the resulting yarn was employed to produce acut pile carpet, the resulting carpet showed a pleasing velvety sheen.

A tufted loop pile carpet twisted 2S-2Z from 1200 denier 70-filamentcrimped yarn as above described having the trilobal cross section ofOpfell U.S. Pat. 3,216,186 was found to approximate closely thecharacteristics of wool carpets.

The carpets produced from the above yarns showed good dyeability,especially with disperse anthraquinone dyes, and had good dyeuniformity. The cover was exceptional; and in all respects these carpetswere of high quality.

We claim:

1. A process for producing textured yarn which comprises:

(a) extruding through a multihole spinnerette a molten dispersion ofpolyester in a fiber-forming polyamide in weight proportions of :10 to60:40 of polyamide: polyester to form a multiplicity of filaments, eachfilament being formed from an extrudate hole providing a capillary areaof 7 l0f to 12x10 square inches;

(b) attenuating the filaments, while in molten condition, by a stackdraw down of about 70 to 120; drawing said filaments aftersolidification to a draw ratio between about 3.5 and :1;

((1) crimping said drawn filaments at an average of at least about 8crimps per inch; and

(e) fully straightening out and stretching the crimped yarn by at leastabout 5 percent beyond said straightened-out length.

2. The process of claim 1 further characterized by imparting to thedrawing filaments about 8 to 17 crimps per inch in a hot zone, coolingsaid crimped filaments and stretching said cooled filaments about 5 to15 percent beyond their straightened-out length.

3. The process of claim 1 wherein the crimping and stretching operationsare correlated to confer crimp elongation off the package not abovepercent while maintaining crimp elongation after boil in the rangebetween and 40 percent.

4. The process of claim 3 wherein the polyester is polyethyleneterephthalate and the polyamide is poly-e-caproamide.

5. The process of claim 4 wherein the polycaproamide has a relativeviscosity in aqueous 90 percent formic acid in the range of 50 to 100 byASTM Test D-789-62T and has about 5 to milliequivalents of primary aminoend groups per kilogram of polycaproamide.

6. The process of claim 5 wherein the filaments are formed from a groupof three closely spaced capillaries to produce a multilobal crosssection.

7. The process of claim 6 wherein the filaments are extruded into aquiescent atmosphere maintained at a temperature of about 320 to 380 C.at a distance about onehalf inch below the spinnerette.

8. The process of claim 2 wherein the crimping is effected in astuifer-box crimper.

9. The process of claim 3 wherein the textured yarn is cut into staplefibers and spun into a yarn suitable for tufting.

10. The process of claim 3 wherein the textured yarn is tufted to form apile article.

References Cited UNITED STATES PATENTS 3,143,784 8/ 1964 Scott.3,361,859 1/1968 Cenzato. 3,382,305 5/1968 Breen. 3,399,108 8/1968Olson. 3,447,308 6/1969 Fungijin et al. 3,470,686 10/1969 Fleming et a].3,489,832 7/1970 Bruton et a1.

DONALD J. ARNOLD, Primary Examiner J. H. WOO, Assistant Examiner US. Cl.X.R.

